Though the 30-year-old Internet sensation gained attention thanks to her unbelievably fit pregnant body, it's still shocking to see her get into a skimpy white two-piece bikini just three weeks after giving birth. Sarah posted a sexy selfie on Monday, calling attention to her thrifty swimsuit -- but it's safe to say pretty much everyone was more focused on her svelte physique.

"Can we talk about how this @shopflynation bikini is only $20?! #postpartum #MomLife," she captioned the stunning photo.

The new mom did give a clue as to how she might be getting a bit of help getting her amazing shape back so quickly. Last week, she Instagrammed a picture of herself in a corset, getting in on the Hollywood waist training trend made popular by celebs like Kim Kardashian and Ciara.

In March, the controversial model talked to ET, when she addressed the critics who claim she's not being healthy.

"The doctor said my baby is healthy," she also pointed out. "All my girlfriends that are pregnant now, their bellies are a lot bigger, so I asked him and her started laughing. He was like, 'You're fine.'"

Sarah said that she gained 28 pounds during her entire pregnancy, and baby James weighed in at a healthy 8 lbs. 7 oz. and was 22 inches long at birth.